(Not Applicable)
(Not Applicable)
The present invention relates generally to milling metal and other suitable substrates and more particularly to a method of preparing thin supported films by vacuum deposition and chemical milling.
Chemically milling substrates is known in the art. For example, patterns can be chemically etched in metal substrates leaving holes in the shape of the pattern in the substrate. Many applications, such as laser beams, semi-conductors and integrated circuits require that the holes in the substrate be covered with a thin film. Prior art systems use a two-step process to accomplish this. First, the substrate is etched, resulting in a substrate with one or more holes in the substrate. Second, a thin film is attached to one side of the substrate so that the thin film covers the holes. This process is problematic in that the thin film initially must be supported in some manner and then attached to the substrate. This process is prone to errors, such as damaging the film during the transferring and adhering process.
Therefore, a need exists for a system of producing an etched substrate with a thin film covering without having to transfer the thin film to the etched substrate.
The present invention is directed to a method for preparing thin supported films by vacuum deposition. The method results in a substrate with a window or windows. The windows are cutout (etched) areas which are covered by a thin film. The method for creating the substrate with thin film covered areas requires: masking off one surface of the substrate with a maskant; placing the substrate under a vacuum; treating the unmasked surface by plasma etching to clean and enhance adhesion; coating the treated surface with a film while still under vacuum; removing the substrate from vacuum; removing masking; treating the previously masked side with photo resist; exposing the side treated with photo resist to artwork of a desired pattern; then exposing the substrate to a suitable solution; chemically etching in areas selectively exposed by the artwork and then neutralizing the substrate.
In accordance with other aspects of the invention, the substrate is a meta. The metal may be stainless steel, brass, silicon or other materials.
In accordance with still other aspects of the invention, the maskant can be tape, liquid film, wax, or other types of resists.
In accordance with yet other aspects of the invention the film is produced by vapor deposition or plasma arc deposition. Preferably, the film is parylene, or one of the many types of clear plastic films produced by low-pressure chemical or vapor deposition.